1. Field of Invention
The present invention relates to a method, and apparatus for performing such method, of image processing to detect and enhance edges and to reduce noise in ultrasound imaging. Specifically, the method relates to the detection of edges in noisy images and the enhancement the edges and the image.
2. Description of Related Art
An ultrasound image consists of back-scattered signals from many scatterers in the sample volume (or image cell). Interference effects of these many signals may enhance signals or cancel each other, creating grainy images. These grains are called speckles and thus the ultrasound image is represented by these grains or speckles even if the imaged area is considered to be homogeneous tissue with monotone contrast. In such instances, the ultrasound image looks noisy as the true tissue is hidden behind this curtain of grain noises absent image processing to remove the noise. Generally, a smoothing filter is applied to the ultrasound image to reduce speckles by smoothing out grains or noises. In the middle of an organ, such as a liver, liver tissue may be considered homogenous and thus should have monotone contrast and speckles in this area should be smoothed. If the same smoothing filter is applied to the liver borders or all areas in the image, the liver borders or edges become blurred or fuzzy.
What is therefore needed is a method for determining if a pixel in an image represents a homogeneous tissue area to which a smoothing algorithm should be applied.